Fig. 6

Immune cell infiltration analysis and validation. A The composition and abundance of immune cells in lung tissue from non-smokers, smokers, and COPD patients. B Double immunofluorescence staining analysis of lung tissues from smokers without COPD and smokers with COPD. Cells with both red and green fluorescence indicate NK cells or M2 macrophages. Scale bar: 50 μm. *P < 0.05, **P < 0.01, ***P < 0.001